I have a 5V (TTL level) FTDI Cable already and just wanted to know if this would possibly damage any of the components on this watch. I realize that the 3.3V FTDI cable does provide a 5V power wire, but that the rx, tx and the other signals are at 3.3V levels. The 5V FTDI cable I have provides rx, tx, and the other signals at 5V (TTL) levels.

Also, when you connect the FTDI cable to program the watch, should you make sure to remove the coin battery first?